Fix unused variable in CoroFrame.cpp when building Release with GCC 10

[dpaoliello]

Summary

When building with GCC 10, the following warning is reported:

/llvm-project/llvm/lib/Transforms/Coroutines/CoroFrame.cpp:1527:28: warning: unused variable ‘CS’ [-Wunused-variable]
 1527 |       if (CatchSwitchInst *CS =

This change adds a cast to void to avoid the warning.

[dpaoliello]

@lxfind Can you please merge this in?

[AlexeySachkov]

llvm/lib/Transforms/Coroutines/CoroFrame.cpp

1538

I wonder, why do we need the second (void)CS if we already had one on line 1542 right within the same if?

[lxfind]

llvm/lib/Transforms/Coroutines/CoroFrame.cpp

1538

hah looks like this was fixed in https://github.com/llvm/llvm-project/commit/fb98a1be43645c87fff089c4cc9555ca2400268c a day before this commit

llvm/lib/Transforms/Coroutines/CoroFrame.cpp

static void rewritePHIs(BasicBlock &BB) {
   // Special case for CleanupPad: all EH blocks must have the same unwind edge
   // so we need to create an additional "dispatcher" block.
   if (auto *CleanupPad =
           dyn_cast_or_null<CleanupPadInst>(BB.getFirstNonPHI())) {
     SmallVector<BasicBlock *, 8> Preds(predecessors(&BB));
     for (BasicBlock *Pred : Preds) {
       if (CatchSwitchInst *CS =
               dyn_cast<CatchSwitchInst>(Pred->getTerminator())) {
+        (void)CS;
         // CleanupPad with a CatchSwitch predecessor: therefore this is an
         // unwind destination that needs to be handle specially.
         assert(CS->getUnwindDest() == &BB);
         (void)CS;
         rewritePHIsForCleanupPad(&BB, CleanupPad);
         return;
       }
     }